JP7163638B2 - Print media group, method for manufacturing print media group, and method for collating print media - Google Patents

Description

The present invention relates to a print medium group, a print medium group manufacturing method, and a print medium collation method.

In recent years, for the purposes of traceability, product introduction, guarantee seals, lotteries, quality assurance, etc., several methods have been developed to attach different codes (medium with identification information or unique information) or identification marks to each product. ing. These include examples of printing two-dimensional codes such as barcodes and QR codes as different codes for each product, and examples of reading individual differences such as artifact metrics.

As an example of pursuing traceability using a two-dimensional code as an individual code, there is a technique as described in Patent Document 1, for example. Also, as a method of performing authentication using artifact metrics, there is a technique described in Patent Document 2 and the like. Furthermore, Japanese Patent Laid-Open No. 2002-200010 discloses a technique using moire patterns due to periodic structures of fibers and metals as artifact metrics.

JP 2011-210663 A JP 2016-85679 A JP-A-2003-29636

By the way, when common product information is included in barcodes, QR codes, etc., the same barcodes and QR codes may be uniformly printed on product packages. For this purpose, a mass printing method, such as offset printing, gravure printing, letterpress printing, intaglio printing, screen printing, etc., which can print a large amount of the same pattern using a common printing plate at low cost, is suitable.

On the other hand, in systems that pursue traceability of products such as perishables, individual information for each product such as quality, weight, size, date of production (hereinafter referred to as “unique (also referred to as “information”) is required to be added to product packages of perishable foods. However, when trying to print such product-specific information on a product package or the like, it is necessary to individually prepare patterns and identification marks to be printed in accordance with the product-specific information.

For this reason, it has been considered difficult to apply a mass printing method using a common printing plate as described above. Therefore, when printing such product-specific information on product packages, etc., after converting the product-specific information into individual print content, laser printing, inkjet, thermal transfer, etc. are used. Different patterns had to be printed separately. However, these printing methods are generally expensive and take a relatively long time to print, so there is a problem that they are not suitable for printing product packages that are required in large quantities.

In addition, since the printed product-specific information can be easily duplicated using a scanner, digital camera, etc., there is also the problem that product-specific information on another product package can be easily replaced. rice field.

On the other hand, instead of the method of printing different patterns individually, there is also a method of using artifact metrics. As a known artifact metric, for example, Patent Document 2 discloses a method of recognizing halftone dots produced by printing. However, when using artifact metrics, it is necessary to recognize minute pattern changes, so a high-resolution reading device is required for pattern detection, and a high-performance computing system is required for matching. was becoming Also, if the medium is scratched or soiled, there is a possibility that an erroneous determination may occur.

Furthermore, Patent Document 3 proposes a moire pattern generated by a random periodic structure of fibers, metal wires, etc., but it has the disadvantage that its production is complicated and expensive compared to ordinary printing. In addition, since the pattern is arranged three-dimensionally in this prior art, the pattern to be read may change depending on the reading position of the reading device, resulting in an erroneous determination.

In addition, it is difficult to generate individual codes directly on the product itself or product packaging with conventional individual codes that are generated by non-printing methods. It was also a cause of fraud such as attaching and detaching the tag and re-sticking the sticker.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems in the prior art and to provide a group of print media that can be identified with higher accuracy using a moire pattern, and a method of manufacturing the group of print media.
Another object of the present invention is to provide a printing medium collation method capable of identifying a moire pattern with higher accuracy.

According to one aspect of the present invention, in a print medium group consisting of at least two print media,
The print medium has a moire pattern generated by overlapping at least two periodic patterns commonly used in the print medium group,
The print medium includes an area marker commonly used for the print medium group,
The print media are identifiable by differences in the moire patterns.

According to one aspect of the present invention, a method of matching a print medium comprises:
A matching method for matching a first print medium and a second print medium, each having a moire pattern and a common area marker, comprising:
a substep of generating first print image data from the first print medium;
a sub-step of extracting a first moiré pattern and area markers from the generated first print image data and storing them as first moiré information;
a substep of generating second print image data from the second print medium;
a second extraction step comprising: a sub-step of extracting a second moiré pattern and area markers from the generated second print image data and storing them as second moiré information;
a matching step of matching the first moiré information and the second moiré information,
In the matching step, a first relative relationship between the first moiré pattern and the area marker obtained based on the first moiré information, and the second moiré pattern obtained based on the second moiré information. comparing two moire patterns with a second relative relationship with the area marker;
If the first relative relationship and the second relative relationship match, it is determined that the first print medium and the second print medium are the same.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the printing-medium group and the printing-medium group which can be distinguished more accurately using a moire pattern can be provided.
Further, according to the present invention, it is possible to provide a printing medium collation method capable of identifying a moire pattern with higher accuracy.

FIG. 10 is a diagram showing a neighborhood region for a periodic pattern; FIG. 4A is a diagram of a first periodic pattern that constitutes a moire pattern; FIG. 10 is a diagram of a second periodic pattern and area markers that make up a moire pattern; FIG. 4 is a diagram of a moiré pattern consisting of a first periodic pattern and a second periodic pattern; FIG. 10 is a diagram showing another example of a moire pattern; FIG. 10 is a comparison diagram near an area marker of moiré patterns in which the overlapping positions of the first periodic pattern and the second periodic pattern are different; 1 is a schematic diagram showing an information communication system to which a matching system using moire patterns is applied; FIG. FIG. 4 is a sequence diagram showing the operation of the matching system; 4 is a flow chart showing moire extraction; FIG. 4 is a diagram showing an example of moire regions determined by area patterns; FIG. 11A is a diagram showing an example (a) in which two area markers are added to the second periodic pattern, and an example (b) of the generated moiré pattern. FIG. 4 is a diagram showing an example of moire regions determined by two point area markers; 10 is a flowchart showing moire extraction when there are two area markers; FIG. 12A is a diagram showing an example (a) in which three area markers are added to the second periodic pattern, and an example (b) of the generated moiré pattern. FIG. 4 is a diagram showing an example of moire regions determined by three point area markers; 10 is a flowchart showing moiré extraction when there are three or more area markers; FIG. 10 is a diagram showing another example of area markers and moire patterns; FIG. 10 is a diagram showing another example of area markers and moire patterns; FIG. 10 is a diagram showing another example of area markers and moire patterns; FIG. 10 is a diagram showing another example of area markers and moire patterns; FIG. 10 is a diagram showing another example of area markers and moire patterns; FIG. 10 is a diagram showing another example of area markers and moire patterns; FIG. 10 is a diagram showing another example of area markers and moire patterns; FIG. 4 is an enlarged view of a moire pattern consisting of a first periodic pattern and a second periodic pattern each consisting of a closed curve, and area markers; FIG. 10 is a comparison diagram of moiré patterns in which the overlapping positions of the first periodic pattern and the second periodic pattern are different; FIG. 10 is a diagram showing an example in which the sizes of regions in which the first periodic pattern and the second periodic pattern are formed are different; FIG. 10 is a diagram showing another example in which the sizes of regions in which the first periodic pattern and the second periodic pattern are formed are different; 4 is a flowchart for explaining a process of creating a print medium; FIG. 3 is a perspective view of a beverage package as a print medium; 2 is a cross-sectional view showing the configuration of a print medium; FIG. 1 is a side view showing the configuration of a print medium manufacturing apparatus; FIG. 1 is a conceptual diagram of a traceability system using a collation system; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on the drawings. The embodiments shown below are examples of devices and methods for embodying the technical idea of the present invention. is not specific to Various modifications can be made to the technical idea of the present invention within the technical scope defined by the claims.

As used herein, the term “periodic pattern” refers to a pattern having one or more peaks at frequencies other than 0 when the pattern is decomposed into spatial frequency components using Fourier transform or the like.

"Moiré pattern generated by overlapping two periodic patterns" refers to the formation of moiré patterns by physically overlapping periodic patterns formed in multiple processes, as well as the synthesis of two periodic patterns on image data. The above also includes outputting a moire pattern as one image. It is preferable that the periodic patterns to be superimposed are substantially identical to each other. Approximately the same periodic pattern is the same periodic pattern that has undergone a change in scale, deformation, rotation, or the like. Moreover, these periodic patterns can form various moiré patterns by superimposing them by performing displacement, inclination, deformation, and the like. It should be noted that the periodic patterns to be superimposed are not limited to being substantially the same, and any pattern that causes moire by superimposing the periodic patterns may be used.

However, in the following embodiments, overlapping of periodic patterns formed through a plurality of printing processes on a print medium will be mainly described. Any method can be adopted as a printing method for printing the moire pattern.

As used herein, the term "area marker" refers to one or both of the periodic patterns, which are located inside or near each other, and by using a reference point within the area marker, the moire can be identified by its relative position to the moire. It is a possible pattern. In other words, the area marker can be used as a reference when analyzing moire generated by overlapping periodic patterns. Area markers preferably have a different frequency than the periodic pattern.

The shape of the area marker is preferably a pattern consisting of a combination of arcs, straight lines, vertices, and corners. Examples include figures such as asteroids and stars, characters, symbols, logotypes and illustrations.

Note that "near the periodic pattern" is within a circle having a radius equal to the maximum width of the area provided with the periodic pattern from the center of the area provided with the periodic pattern (the center of gravity in the case of a free shape). Specifically, in the example of FIG. 1, the maximum width 201 in the region 200 provided with the periodic pattern by the periodic pattern 206 is the length indicated by the black line. From this center point 202, the area within the circle having the maximum width as the radius is the neighboring area 205 of the periodic pattern, and the area marker 9 is assumed to be positioned within this circle. The area marker 9 may be outside the area in which the periodic pattern is provided, or may be inside the area.

An arbitrary figure can be used for the area marker. Also, it is preferable that the area marker is larger than the minimum unit of the periodic pattern, and the total area of the area markers is within 95% of the area of the periodic pattern.

In this embodiment, an area marker is provided inside or near the moiré pattern. At this time, the positional relationship, distance, size ratio, etc. between the generated moire pattern and the area marker can be determined. , can support the analysis of infinitely occurring moire patterns.
In addition, since an arbitrary figure can be used, it is possible to use a design that reduces the sense of incongruity, glaring, etc. of the generated moire pattern, or conversely, a design that utilizes it.

(Example of moire pattern)
In the example below, two periodic patterns are used to form a moire pattern. FIG. 2 is a diagram showing a first periodic pattern 220. As shown in FIG. FIG. 3 is a diagram showing the second periodic pattern 230 and area markers 900. As shown in FIG. The first periodic pattern 220 is a pattern in which concentric circles whose radii change at equal intervals are formed in a rectangular frame (region). On the other hand, the second periodic pattern 230 is also a pattern in which concentric circles whose radius changes at the same intervals are formed within a rectangular frame (region), but is a concentric pattern reduced to 92% of the first periodic pattern. Here, concentric circles are used as an example of a closed curve, but the closed curve may be an ellipse, a polygonal shape, or a closed free curve. Also, although the area marker 900 is a filled rectangle, it may be a figure with only an outer frame.

Since the first periodic pattern 220 and the second periodic pattern 230 each have a periodic structure, when the periodic structures are approximated to each other, when one period of the first periodic pattern is 1, the circle is A moiré pattern 240 is generated as shown in FIG. 4 by moving the center by 4.5 periods in the y-axis direction (vertical direction in the figure) and printing in an overlapping manner.

Further, in FIG. 5, only the second periodic pattern 230 is further shifted by one period in the y-axis direction from the moire pattern in FIG. A moire pattern 242 is shown that is generated by moving 5.5 periods in the y-axis direction and printing in an overlapping manner. In this way, in the same combination of periodic patterns, the moire pattern changes with a minute relative movement.

At this time, moire patterns, which consist of minute shifts and distortions in combinations of the same periodic patterns, often resemble each other, and it is conceivable that misjudgments may occur during the process of reading and matching moire patterns. By doing so, it is possible to improve the distinguishability of the pattern.

6(a) is an enlarged view near the area marker 900 in FIG. 4, and FIG. 6(b) is an enlarged view near the area marker 900 in FIG. Comparing FIGS. 6A and 6B, it is clear that the positions of the moire fringes crossing the area marker 900 are different, and thus the moire fringes are different. Thus, by using the area marker as a reference rather than analyzing the moire pattern from the entire periodic pattern, it is possible to improve the accuracy and speed of analyzing whether the moire fringes are the same.

(matching system)
An example of a printing medium matching method for realizing a matching system using a moiré pattern will be described below. For example, print media such as product packages are often manufactured in a printing factory, but products are often manufactured in a separate product manufacturing factory or the like. In such a case, when packaging a product manufactured in a product manufacturing factory, the moire pattern printed on the package is optically read and converted into image data (moire information). After that, the image data and the product information in the package are associated with each other and individually stored in a printing pattern matching device, which will be described later. The image data including the moire pattern and the area marker is here referred to as moire information.

The process of extracting and storing the moire information (first moire information) at the product manufacturing factory is called a first extraction process. A process of reading the markers to extract and store moire information (second moire information) is called a second extraction process.

As shown in FIG. 7, for example, the verification system 1 captures or scans a plurality of print media 2 attached to a product (not shown) and on which a moire pattern is printed, and prints the print media image data by photographing or scanning the print media 2. (including moire pattern data and area marker data), a communication terminal 3 for transmitting print medium image data, a communication path 5 realized by a mobile phone communication network, the Internet network, etc., and the communication path It consists of a connectable print pattern matching device 4 . Note that the reading device 3a may be configured integrally with the communication terminal.

The print pattern matching device 4 receives print medium image data transmitted from the communication terminal 3, and includes an inquiry information storage unit 410 for storing the received print medium image data, and a photographed image correction unit for correcting the stored print medium image data. a moire pattern extraction unit 420 that extracts moire information from the print medium image data stored in the inquiry information storage unit 410 using area markers; Moiré pattern collation for collating the moiré information stored in the base information storage unit 430 and the moiré pattern extraction unit 420 storing the product information associated with the moiré information with the moiré information saved in the base information storage unit 430 It has a part 440 .
It is assumed that the inquiry information storage unit 410 stores in advance the shape of the area marker attached to the print medium as area marker data. Furthermore, in the following example, it is assumed that, for example, at the time of shipment from the factory, the print medium attached to the product is photographed, the moire information is extracted, and the inquiry information storage unit 410 stores the moire information. The "first print medium" and the "second print medium" may or may not be the same.

FIG. 8 is a ladder chart showing the operation of the matching system. After the product on which the moire pattern is printed is sold, for example, the consumer operates the reading device 3a of the communication terminal 3 to photograph the print medium 2 attached to the product (step S110), and print it via the communication path 5. Assume that the medium image data is transmitted to the print pattern matching device 4 . In response, the inquiry information storage unit 410 of the print pattern matching device 4 receives the transmitted print medium image data (step S120). Subsequently, the moire pattern extraction unit 420 extracts moire information (second extraction step) from the received print medium image data (step S130).

In the moire pattern extraction unit 420, collation (collation process) is performed according to the flowchart shown in FIG. 9 as an embodiment. First, the print medium image data acquired in step S120 is read as an input image (step S131), and the inside and the vicinity of the periodic pattern are searched based on the shapes of the area markers pre-stored in the inquiry information storage unit 410 (step S132), the area marker is extracted (step S135). When the area marker is extracted, a region (also called a search region) to be used for moire pattern discrimination is determined from the position of the area marker (step S133). The moiré pattern in the area determined by the area marker is extracted and used as moiré information (step S134).

The area used for determining the moire pattern based on the position of the area marker is set according to the shape of the area marker and the position of the periodic pattern. The area used for moiré pattern determination may be determined based on the size of the area marker from any reference point (center, center of gravity, etc.) of the area marker.

For example, when analysis is performed on a printed group of a combination of the periodic pattern in FIG. 2 and the periodic pattern in FIG. 3, and the image obtained as print medium image data has the moire pattern shown in FIG. FIG. 10 shows an example of an area determined as a region to be used for moire pattern discrimination from the position of .

In the example of FIG. 10, the area marker 900 is rectangular and exists on a periodic pattern, and the moire 240 is also generated to include the area marker 900 . Therefore, the center of gravity of the area marker 900 is set as a reference point 290 for the moiré area determination process, the direction parallel to the opposing sides of the area marker 900 (vertical direction in the figure) is set as the first direction, and the other direction parallel to the opposite side ( When the horizontal direction in the figure is defined as the second direction, the area 90 used for the moire pattern is set to be three times the size 90Y and 90X in each direction. However, the area used for analysis is not limited to this.

The reference point of the moire area determination process in the area marker is located on the same plane as the area marker on the print medium,
The point is that the position can be uniquely defined from the shape and relative positional relationship of each area marker.

It may also be determined by the minimum number of repetitions of the periodic pattern, or the direction, period, number, etc. of moire fringes that are mainly generated. It is desirable that the periodic pattern be repeated at least twice within the region 90 and that the density of the generated moiré be included in 0.5 periods.

In FIG. 8, the moiré pattern matching unit 440 extracts moiré information (second moiré information) in this way, moiré information (first moiré information) stored in the basic information storage unit 430, and " (also referred to as "matching moiré information data") (step S140), and extracts the same moiré information as the extracted moiré information from the matching moiré information data stored in the basic information storage unit 430. . For example, by executing image processing within the area 90, if the relative positions (relative relationships) of the moire fringes extending from each side of the area marker match each other, the moire pattern matching unit 440 determines that the moire information is the same. It is determined that the On the other hand, if the relative positions of the moire fringes do not match, the moire pattern matching unit 440 determines that the moire information does not match.

In the moire pattern extraction unit 420 and the moire pattern matching unit 440, methods such as Fourier transform, template matching, edge detection, and vector correlation may be used as embodiments for extracting and matching moire patterns, as described above. By using the area marker to determine the area to be used for analysis with respect to the print group, it is possible to improve the speed and accuracy of moire detection and collation.

If the same moire information can be extracted, the moire pattern matching unit 440 performs authentication processing for the print medium 2 (step S150 in FIG. 8), and the associated product information (product manufacturing date, etc.) A reply is sent to the communication terminal 3 of the transmission source.
At this time, the moire pattern matching unit 440 first transmits to the communication terminal 3 affirmative information indicating that the same moire information has been extracted. As long as the product information is transmitted to the communication terminal 3 .

On the other hand, if the print pattern matching device 4 cannot find the same moiré information as the moiré pattern stored in the print pattern specifying unit in the print pattern storage unit, the moiré pattern matching unit 440 determines that the same moiré information does not exist. Negative information indicating that there was not is sent back to the communication terminal 3. In response, the communication terminal 3 displays the sent determination result on a display (not shown) (step S160 in FIG. 8).

According to the present embodiment, the reading device 3a of the communication terminal 3 is, for example, a camera using an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The reading device 3a only needs to have accuracy capable of detecting differences between a plurality of moire patterns, and does not require a high-performance lens or imaging device.

(Example of area marker)
Also, the number of area markers may be two. When the number of area markers is two, the matching accuracy can be further improved and the design can be improved more than when the number of area markers is one. Two area markers used at the same time may have the same shape or may have different shapes.

FIG. 11(a) is a diagram showing a first periodic pattern 220 and area markers 900 and 901. FIG. Here, area marker 901 is the same size as area marker 900 and is a filled rectangle. FIG. 11(b) shows a moiré pattern 243 generated by shifting FIG. 11(a) by 4.5 cycles in the y-axis direction (see FIG. 2).

When analyzing a moire pattern using two area markers, two area markers are extracted from the captured image data (step S135 in FIG. 13), and the positions of the area markers are used for moire pattern discrimination. An area is determined at each of two points, and moiré in the area determined by the area marker is extracted and used as moiré information. Here, when analyzing a moire pattern using two area markers, a method using both area markers themselves, a method using a space between the two area markers, a method using both area markers themselves, and a space between the two area markers. You can choose any one of the techniques that use intervals.

As a result, the moiré pattern collating section can improve collation accuracy by comparing the moire patterns of the areas determined by the respective area markers, and collation can be performed even if one of the area markers cannot be read due to dirt or the like. be able to.

FIG. 13 is a flow chart for extracting moiré information by the moiré pattern extractor 420 when there are two area markers. The processing up to the detection of the area marker (step S135) is the same as in the above-described embodiment, so redundant description will be omitted.

In step S140, a moire pattern analysis method is selected. Specifically, when the method using both area markers themselves is selected, the moire patterns are analyzed for both area markers as described above (step S141), and the moire patterns are determined by both area markers. Moiré patterns can be determined to be identical only when they are determined to be identical. Thereby, highly accurate determination can be performed.

On the other hand, in step S140, when the method using the space between the two area markers is selected, the area markers are extracted from the two points, and then the area used for moire pattern discrimination is selected from the area marker positions. Between each reference point (closest point) of the two points. For example, it is also possible to extract the number and positions of moire lines intersecting a line segment connecting two reference points of the area marker, and compare them as moire information (step S142). In this case, by obtaining moiré information from the relationship between two points, it is possible to perform accurate collation even when printing is distorted or stretched.

Further, in step S140, when the method using the space between the two area markers and using both area markers themselves is selected, the method using the space between the two area markers similar to the above (step S143) and the method using both The method using the area marker itself (step S144) can be continuously executed.

Here, examples of analysis methods include counting and comparing the number of moire fringes passing between two area markers, comparing the brightness at an arbitrary point such as the middle point between two area markers, The first axis is the distance between two points, the second axis is the brightness of the moire fringes, and the shape of the waveform tracing the numerical values is compared. The first axis is the distance between the two area markers, and the second axis is the brightness of the moiré fringes. and frequency analysis of the waveform that traces the numerical value.

FIG. 12 is an enlarged view near the area markers 900 and 901 in FIG. 11(b). Among the vertices of the area markers 900 and 901, the vertices (closest points) closest to the other area marker are set as reference points 291 and 292 for the moiré area determination process, and the line connecting the two points is the area used for moiré pattern determination. 91.

Also, the number of area markers may be three or more. When the number of area markers is three or more, accuracy and design can be improved more than when the number of area markers is one or two. At this time, each area marker may have the same shape or may have a different shape.

Here, when analyzing a moire pattern using three area markers, a method using each area marker itself, a method using a line segment between two area markers, and a triangular area between the three area markers are used. Either method or a method combining the above methods can be selected.

FIG. 14(a) shows a first periodic pattern 220 and area markers 900-902. Area marker 902 is the same size as area markers 900 and 901 and is a solid rectangle. FIG. 14(b) shows a moire pattern 244 generated by shifting FIG. 14(a) by 4.5 cycles in the y-axis direction (see FIG. 2).

FIG. 16 is a flow chart for extracting moiré information by the moiré pattern extractor 420 when there are three area markers. The processing up to the detection of the area marker (step S135) is the same as in the above-described embodiment, so redundant description will be omitted.

In step S140, a moire pattern analysis method is selected. Specifically, when the method using each area marker itself is selected, the moiré pattern is analyzed for each area marker as described above (step S145), and the moiré pattern is determined to be identical for each area marker. Only when it is determined, the moire patterns can be determined to be the same.

On the other hand, in step S140, when the method using the space between the two area markers is selected, a line segment (three sides of a triangle) is formed between the reference points of the two area markers, so a total of three line segments are obtained. The number and position of moire lines can be extracted for each area corresponding to the line segment and compared as moire information (step S146). This makes it possible to improve the accuracy of identity. Alternatively, verification can be performed even when some area markers cannot be read due to dirt or the like.

In addition, when the method using the space between the three area markers is selected in step S140, the surface (triangular area) formed by the reference points of the three area markers is set as the area used for determining the moire pattern, and the three reference points It is also possible to extract moiré in the plane and use it as moiré information (step S147). In this case, by obtaining moire information from the relative relationship of moire fringes with respect to a triangular area made up of three reference points, it is possible to perform accurate collation even when printing is distorted or stretched.

In FIG. 15 shown as an example, reference points (closest points) 293 to 295 for the moiré area determination process are set for each of the area markers 900 to 902, respectively, and a plane formed by lines connecting the reference points is used for moiré pattern discrimination. This is the area 92 to be used.

In addition, if a combination of the above-described methods is selected in step S140, identity can be determined by combining these methods (step S149).

When there are a plurality of area markers, the reference point of the moire area determination process for the area markers is preferably the point closest to the other area markers, particularly among the vertices of the area markers. In this case, it is possible to maintain the accuracy of the area determined by the area marker. Also, when connecting area markers, it is preferable that the route does not pass over the area markers.

Also, the area markers may be arranged in a shape surrounding the periodic pattern or arranged around it. At this time, the periodic pattern can be well blended into the pattern, and the design can be enhanced.

As an example, FIG. 17A is a diagram showing a grid-like first periodic pattern 221 and area markers 910 . The area marker 910 is painted in a donut shape surrounding the area of the first periodic pattern. FIG. 17(b) shows a second periodic pattern 231 that is 92% smaller than the first periodic pattern. 17(a) and 17(b) are superimposed and printed, a moire pattern 245 is generated as shown in FIG. 17(c).

The shape of the area marker may have one or more vertices. In analysis using area markers, the position and inclination of the area markers can be easily recognized by the vertices.

As an example, FIG. 18A is a diagram showing a linear first periodic pattern 222 and area markers 920 and 921. FIG. Area markers 920 and 921 are filled with cones (droplets) having one vertex. FIG. 18(b) shows a second periodic pattern 223 obtained by reducing the first periodic pattern 222 by 92%. 18(a) and 18(b) are superimposed and printed, a moire pattern 246 is produced as shown in FIG. 18(c).

The shape of the area marker may be polygonal. It may also contain stars and curves. If there are multiple vertices, it is possible to make it easier to recognize the position and inclination of the area marker. Also, when a plurality of area markers are used, it is possible to select a vertex most suitable for analysis, such as being close to other area markers, as a reference point, thereby further improving accuracy.

As an example, FIG. 19(a) is a diagram showing a linear first periodic pattern 222 and area markers 930-933. Area markers 930 and 931 are polygonal, area marker 932 is an asteroid (star-shaped), and area marker 933 is star-shaped. 19(a) and 18(b) are superimposed and printed, a moire pattern 247 is generated as shown in FIG. 19(b).

Also, the area marker may be an illustration such as a character, a letter, a logo, or the like. By combining it with a pattern, moire can be naturally used as a pattern, and it is possible to reduce the moire from becoming an unpleasant pattern for humans.

As an example, FIG. 20( a ) is a diagram showing the same first periodic pattern 220 as in FIG. 3 and area markers 940 . Area markers are filled in with character shapes. By printing the same first periodic pattern 220 as in FIG. 2 over the second periodic pattern 230 in FIG. 20(a), a moire pattern 248 is produced as shown in FIG. 20(b).

21A is a diagram showing the same first periodic pattern 220 as in FIG. 3 and area markers 941. FIG. The area marker 941 is filled in in the form of the letter T. By printing the same first periodic pattern 220 as in FIG. 2 over the second periodic pattern 230 in FIG. 21(a), a moiré pattern 249 is produced as shown in FIG. 21(b).

In the above example, the area marker is a solid shape, but it is also possible to extract an arbitrary shape such as a square, circle, or pattern from the pattern and use it as an area marker. In addition, the painted area and the extracted area may be mixed.

As an example, FIG. 22( a ) is a diagram showing the same first periodic pattern 220 as in FIG. 3 and area markers 950 . Area markers 950 are left blank by eliminating periodic patterns in the form of characters. By printing the same first periodic pattern 220 as in FIG. 2 over the second periodic pattern 230 in FIG. 22(a), a moire pattern 250 is produced as shown in FIG. 20(b).

(Example of using a combination of periodic patterns and area markers)
Also, one printed matter may have a plurality of regions provided with the periodic pattern. In particular, when mainly using an illustration, etc., it is also possible to effectively use a moire pattern as a pattern.

As an example, FIG. 23(a) is a diagram in which a design (bear face) 300 includes two concentric first periodic patterns 232 (both ear positions). In this case, the area markers correspond to ranges 960 and 961 included in neighboring regions of the periodic patterns set from the maximum width of each of the first periodic patterns in the pattern 300 .

FIG. 23(b) is a diagram showing a second periodic pattern 233 in which the first periodic pattern 232 is moved. 23(a) and 23(b) are superimposed and printed, moire patterns 251 and 252 as shown in FIG. 23(c) are generated.

At least part of the plurality of periodic patterns may be expressed in different colors, or the colors may be changed within one periodic pattern. In this case, a beautiful pattern with color gradation can be expressed, and a pattern with excellent design can be expressed.

Also, the colors may be different for each part of the plurality of periodic patterns and the area markers. In this case, especially if you use a pattern or logo for the area marker and change the color around the area marker, the moire becomes the background, and even if the moire unintentionally becomes a strange pattern for humans, the design as a whole It can be used naturally.

The above example shows an example of using a closed curve as a periodic pattern. By using such a closed curve at least in part, even if the two periodic patterns are slightly shifted in either direction, the moire pattern will change significantly, making it possible to generate a highly identifiable pattern. Become. On the other hand, by using an open curve instead of a closed curve for at least a part of the periodic pattern, it becomes possible to increase the degree of freedom in design, and it is possible to obtain a pattern excellent in terms of design. Combining closed and open curves is optional.

In the examples described above, examples of moire patterns generated from curved lines and moire patterns generated from straight lines are shown, but the present invention is not limited to these, and may include combinations of curves and straight lines, halftone dots, and the like. Any combination of periodic patterns such as halftone dots, halftone dots and curved lines, and halftone dots and straight lines may be used as long as it produces a moiré pattern. Halftone dots can be easily generated by a normal process printing plate making system. In addition, by changing the area and density of halftone dots, or by changing the width of lines, it is possible to superimpose and express shaded patterns.

In this example, the same color is used for the first periodic pattern, the second periodic pattern, and the area markers. In this case, there is an advantage that the contrast of the generated moire pattern is increased, and when the moire pattern is provided with identification information or unique information, it is easy to recognize it.

In this example, an example of a combination of two periodic patterns is shown as a moiré pattern, but the moiré pattern may be generated by combining three or more periodic patterns.

By forming each periodic pattern on the same surface of the base material, even if the reading position of the reading device described later changes, the moire pattern changes little, enabling reading with less erroneous determination. In order to protect the printed surface, a transparent protective layer may be provided on the surface where the moire pattern is generated, or the moire pattern may be observed from the back surface of the transparent substrate.

(Decomposition of moire pattern)
In some cases, the moire pattern after printing can be decomposed into the first periodic pattern used for printing, the second periodic pattern, and the area marker. In such a case, if there is one moiré pattern, it is possible to accurately estimate the first periodic pattern, second periodic pattern, and area marker used to generate this pattern. The same applies to moire patterns generated from three or more periodic patterns.

(Regarding misalignment of periodic patterns)
FIG. 24 is an enlarged view of the central portion 260 of the moire pattern shown in FIG. In order to change the moire pattern, it is desirable that the minimum distance of print position variation (print misalignment) during printing is 1/10 or more times the average period m of the periodic pattern. This is because the period of the moire pattern is enlarged and changed according to the amount of deviation of the overlapping periodic patterns. Therefore, if the amount of deviation is 1/10 times or more of the average period m of the periodic patterns, the difference between the moire patterns can be easily detected. Because we can judge. Here, the term "print misalignment" refers to the position where the reference points (for example, the centers of concentric circles) of the two periodic patterns formed on the two printing plates with respect to the printing medium coincide with each other. , means to deviate in either direction.

25(a) shows a moiré pattern 240, and FIG. 25(b) shows a first periodic pattern 220 and a second periodic pattern 230 that generate the moiré pattern 240. One period of the first periodic pattern is 1. In this case, the moire patterns 240 generated by printing by moving the center of the circle in the y-axis direction by 4.6 cycles, which is 0.1 cycle more than the moire pattern 240, are shown side by side.
In other words, in the moiré pattern 240(a) and the moiré pattern 241(b), the relative difference in printing misalignment in the y-axis direction between the first periodic pattern and the second periodic pattern is is 1/10.

Here, if the distances from the center of the concentric circles to the center of the first moire fringe in the y-axis direction are p1 and p2, respectively, the deviation amount (relative difference) between the periodic patterns in the two moire patterns is the first periodic pattern However, in the moire pattern, the difference between the distances p1 and p2 is magnified and visible. Therefore, if the minimum distance of variation in printing position during printing is 1/10 times or more the period of the periodic pattern, it is possible to distinguish between moire patterns even with the naked eye. In the case of high-precision image analysis, it is possible to measure the difference between moire patterns if the minimum distance of variation in printing position during printing is 1/50 times or more the period of any periodic pattern.

From this, it can be said that, in creating a moire pattern, it is necessary to set the printing deviation of two periodic patterns to at least 1/50 times or more the average period of one of the periodic patterns.

However, if the deviation of the print position of the periodic pattern becomes considerably large, the first periodic pattern and the second periodic pattern will not overlap, and there is a possibility that the moire pattern will not occur. In order to prevent this, as shown in FIG. 26, if the area in which the second periodic pattern 231(b) is formed is made larger than the area in which the first periodic pattern 221(a) is formed, , even if the printing position is greatly shifted, the displacement of the first periodic pattern 221 within the second periodic pattern 231 will inevitably cause overlap, so that a moire pattern can be generated. However, the deviation of the print position of the periodic pattern must be less than the size of the second periodic pattern 231 (here, half of one side).

The rectangular frame of the first periodic pattern 221 and the rectangular frame of the second periodic pattern 231 are made different in size, and as shown in FIG. By enclosing it in the outer edge, misalignment of the frame when the periodic patterns are superimposed becomes less noticeable, and discomfort to the viewer can be suppressed.

In the embodiment shown in FIG. 27A, in which illustration of the periodic pattern is omitted, the shape of the outermost edge OE1 of the first periodic pattern region is different from the shape of the outermost edge OE2 of the second periodic pattern region. there is Furthermore, part of the outermost edge OE1 of the first periodic pattern protrudes outside the outermost edge OE2 of the second periodic pattern, and part of the outermost edge OE2 of the second periodic pattern extends beyond the first It protrudes outside the outermost edge OE1 of the periodic pattern. This embodiment is an example in which a moire pattern is generated in the central portion of the hexagon where both periodic patterns are superimposed.

At this time, the area marker does not necessarily have to exist at the location where the moire occurs. Regarding the relationship between the area markers and the generated moire, since the area markers are fixed on the pattern, even if the area markers are not in contact with the moire, it is possible to check the change in the relationship with the area markers for each moire change. can.

In addition, in the embodiment shown in FIG. 27B, in which illustration of the periodic pattern is omitted, the outermost edge OE1 of the first periodic pattern area includes the outermost edge OE2 of the second periodic pattern area. More specifically, the entire outermost edge OE1 of the first periodic pattern protrudes outside the outermost edge OE2 of the second periodic pattern. This embodiment is an example in which a moire pattern is generated in the central portion of the circle where both periodic patterns overlap (that is, inside the outermost edge OE2).

(Design and selection of moire patterns)
Next, the design and selection of moire patterns suitable for matching will be described with reference to the drawings. The minimum distance of variation in printing position during printing can be obtained by actually performing printing for a long time or a large number of prints and measuring the positional deviation. "

Further, after printing the product packages, all the product packages are photographed by an electronic camera (not shown), image data of moire patterns (also called moire information) is extracted from the image data of the product packages, and stored in the data storage unit. . Then, in the pre-shipment inspection of the product package, it is possible to check whether the same moire pattern has already been printed (whether two or more of the same moire information are stored). If the same moire pattern is found to be printed, then there may be a step of removing the resulting product packaging, for example.

Such a process will be described in detail using FIG. First, a product package is planned and designed (step S201), periodic pattern data is created (step S203), and pattern data is created (step S204). When creating a periodic pattern, it is desirable to obtain the periodic pattern based on the eigenvalues such as variations in the printing position of the printing machine (step S202). A periodic pattern may be obtained from information on the machine.

For example, in the case of gravure printing that performs printing at 175 lpi (line per inch), it is assumed that the minimum positional deviation is about 10 μm, the period of the first periodic pattern is 90 μm, which is 100 μm or less, and the period of the second periodic pattern is It can be 83 μm, which is slightly smaller than that. These values are used to generate an actual moire pattern, and then determine the final pattern from the design aspect and ease of moire recognition.

Next, a printing plate is created from the obtained data (step S205). Printing is performed using the created printing plate, but the printing of the first periodic pattern (step S206) and the printing of the second periodic pattern (step S207) are performed in different steps. A moire pattern is generated as described above by printing two periodic patterns in an overlapping manner.

It should be noted that different processes may be at least different printing plates, and may be printed with the same printing machine or different printing machines. Here, the printing of the first periodic pattern and the pattern are performed in the same step, but they may be printed in separate steps. Also, the pattern does not need to be printed with one plate, and may be printed in multiple colors with a plurality of plates.

Next, the print pattern including the moire pattern is optically converted into read image data using an inspection device (camera, etc.), etc., and the moire image pattern is extracted and recognized (step S208). By storing it in a data storage unit such as the above, it is possible to collate with the stored image data of the moire pattern each time. If the same moire pattern has already been printed or if there is a defective moire pattern, the print medium is removed (step S209). This avoids confusion during pattern matching. On the other hand, if there is no identical moire pattern, that moire pattern (this is the first stored moire pattern) is stored (step S210), and the process proceeds to the next step.

In the present embodiment, since the print medium is formed by combining periodic patterns, when copying is performed using a scanner, a copier, a digital camera, or the like, the pixels of the imaging elements and the microlens arrays of these image forming apparatuses can be reproduced. A new moire pattern with a periodic structure is likely to occur. Therefore, it can be said that it is difficult to duplicate a print medium having a moire pattern according to this embodiment. In addition, there is a method of using a low-pass filter to avoid moire patterns caused by the characteristics of the image forming apparatus. It becomes possible to determine whether or not it has been duplicated.

(Printing method and printing medium manufacturing method)
Next, a printing method and a printing medium manufacturing method will be described with reference to FIG. The print medium of the present embodiment may be one on which a moiré pattern is printed alone, one printed on a part of a product, or one printed on a part of a product package. "

The print medium 2 comprises a substrate 210 as shown in FIG. As the base material 210, for example, a paper base material or a film base material such as PET (polyethylene terephthalate) can be used. The base material 210 is not limited to a sheet-like one, and the product itself may be used as the base material 210 and the moire pattern may be printed thereon. You can print the pattern. In the following example, the continuous base material sheet 6 is cut after printing to form the base material 210 .

(printing device for printing media)
In FIG. 31, the printing device for printing media includes a plate cylinder 7C for transferring and forming a cyan image, an impression cylinder 7P arranged opposite thereto, and a plate cylinder 8M for transferring and forming a magenta image. , an impression cylinder 8P arranged opposite thereto, a plate cylinder 9Y for transferring and forming an image for yellow, an impression cylinder 9P arranged opposite thereto, and an image for black and a first periodic pattern are transferred and formed. , an impression cylinder 10P opposed thereto, tension rollers TP1 and TP2, an air blowing device DB, and a plate cylinder 11B for transferring and forming the second periodic pattern in black, opposed thereto. and an impression cylinder 11P disposed thereon. Hereinafter, the plate cylinder may be referred to as a printing plate. "

The tension rollers TP1 and TP2 can adjust the tension (pulling force) applied to the base sheet 6 by changing the distance between them by a driving mechanism (not shown). Further, the air blowing device DB incorporates a humidifier for generating water vapor and a heating heater, and sprays moisture-containing air or heated air onto the surface of the base sheet 6 while adjusting the amount of air that is sprayed by a rotating fan. and can be sprayed. These are collectively referred to as positional deviation generators.

The strip-shaped base sheet 6 passes between the plate cylinders 7C to 10B and the impression cylinders 7P to 10P opposed thereto, and after being wound around the tension rollers TP1 and TP2 to apply a predetermined tension. , the air blowing device DB, and further between the plate cylinder 11B and the impression cylinder 11P opposed thereto. At this time, each color image is transferred and formed on the base sheet 6 by the print cylinders 7C to 10B at the same printing timing, and by combining these, a color image of a specific pattern is printed. Although the transfer portion of the area marker is formed on the plate cylinder 11B, the transfer portion of the area marker may be formed on the plate cylinder 10B instead of or together with this.

When the base sheet 6 is passed between the plate cylinders 7C to 10B and the impression cylinders 7P to 10P opposed thereto, registration marks (positioning marks) attached in advance to the width direction end portions of the base sheet 6 ) to control print timing (print position control). Position control at this time includes, for example, a method of controlling the rotational speed of the cylinder and a method of controlling the conveying speed of the base sheet 6, but it is desirable to prevent printing deviation.

On the other hand, on the base sheet 6, the first periodic pattern is transferred and formed in black by the plate cylinder 10B (first step), and the second periodic pattern and area markers are transferred and formed in black by the plate cylinder 11B so as to shift from this. are transferred and formed (second step), and a moire pattern is generated by superimposing them. However, another plate cylinder may be used to form the area markers (third step). After that, the base sheet 6 on which the color image and the moire pattern are formed is individually cut to form a base material 210 (FIG. 30), which is then folded and adhered to form a product package as shown in FIG. 15, for example. be.

In the example shown in FIG. 29, a Japanese sake package is used as the base material 210, and a pattern 310 and a moire pattern 240 are printed on the same base material 210 surface. In this example, an example of a beverage package is shown, but electrical appliances, parts, agricultural products, marine products, processed foods, distribution containers, packing materials such as cardboard, toiletries, cosmetics, software, electronic money, credit cards, prepaid Print media include all kinds of products and product packages, such as cards, gift certificates, replacement parts, and clothing, as well as moving objects such as cars and living things such as pets and livestock.

30, one surface (hereinafter also referred to as "surface") of the substrate 210 has a first periodic pattern 220 as shown in FIG. 1 and a second periodic pattern 230 as shown in FIG. Area markers are printed on top of each other. In the present embodiment, the first periodic pattern 220, the second periodic pattern 230, and the area markers are printed so as to overlap on the substrate 210 at different printing timings.

In a general printing press, positioning of the base sheet 6 is performed by a positioning mechanism or the like in order to avoid printing misalignment. Therefore, even if no particular control is performed, if the alignment mechanism or the like is stopped or if the positioning accuracy is lowered, a certain amount of positional deviation occurs between the first periodic pattern and the second periodic pattern. be able to.

Since the first periodic pattern 220, the second periodic pattern 230, and the area markers are printed on the base material 210 in such a state that they are misaligned, by stopping the alignment mechanism or the like, the printing apparatus can be adjusted. Fluctuations occur due to changes in printing position due to accuracy or the like, expansion or contraction of the base material 210, or the like. The minute variations change the moire pattern 240, and as a result, even if the same pattern is printed, it becomes possible to print different patterns individually. In the case of imposing a plurality of periodic patterns on the same plate for printing, or in the case of exchanging plates in the process, different periodic patterns may be used. In that case, it is possible to easily determine the difference between imposition positions and lots based on the difference in periodic patterns.

However, in order to obtain moiré patterns that are more clearly different, it is desirable to positively cause a positional shift between the first periodic pattern and the second periodic pattern.

Therefore, in the present embodiment, the positional deviation is positively caused between the first periodic pattern and the second periodic pattern as follows. Specifically, in order to change the tension of the base sheet 6 during printing, the interval between the tension rollers TP1 and TP2 is changed between the plate cylinders 10B and 11B, and the air blowing device DB is used to change the tension rollers TP1 and TP2. By blowing air or heated air onto the surface of the base sheet 6, the base sheet 6 can be stretched, and the base sheet 6 can flutter or the like by direct contact with the blown air. This causes a positional deviation between the first periodic pattern and the second periodic pattern.

It is desirable to change the control of the tension roller and the air blowing device (tension force, humidity, temperature, air volume, etc. of the air to be blown) each time the first periodic pattern is formed by the plate cylinder 10B. As a result, the misalignment between the previously formed first periodic pattern and the second periodic pattern can be differentiated from the misalignment between the first periodic pattern and the second periodic pattern formed subsequently. can result in different moire patterns in turn.

According to this embodiment, since the positional deviation is positively caused between the plate cylinders 10B and 11B, the influence does not extend to the upstream side of the plate cylinder 10B. The resulting color image can be formed with high image quality without print misalignment as before. However, if the printing process of the second periodic pattern affects the accuracy of the pattern printing process, after finishing the printing of other patterns, the second periodic pattern and area markers are printed in a separate process. may be performed.

In addition, misalignment between the first periodic pattern and the second periodic pattern and the area markers can also be caused by adjusting the printing device, such as by replacing parts of the printing device. For example, use a plate cylinder with different hardness, cylinder diameter, cylinder inclination or shape (rubber blanket, etc. in the case of offset printing presses), or change the support rigidity of the printing device by changing to a cushioned base. In addition to changing the application of the printing device (guide of the base sheet 6), it is conceivable to vibrate the printing device with an additional device. By the way, the hardness of the blanket can be changed within the range of 73 to 83 degrees measured with a JIS-A hardness tester. By combining the adjustment of the printing device and the drive control of the above-described positional deviation generating device, a larger number of different moire patterns can be generated.

Furthermore, by applying sound waves to the base sheet 6 or by changing the thickness or quality of the base sheet 6, the positional deviation between the first periodic pattern and the second periodic pattern can be generated.

Ink that reflects visible light may be used as the printing ink for the periodic patterns and area markers, or special ink that reflects infrared light or ultraviolet light may be used to hide the moire pattern. good. Alternatively, the moire pattern may be printed directly on the product itself, such as a notebook or calendar, rather than on the product package.

In the above example, an example of a color printing apparatus using four-color process printing is shown as the printing of product package patterns. Also, an independent plate cylinder may be used for printing the first periodic pattern, or a sheet-fed printing apparatus may be used.

The printing plate used for printing the periodic pattern may be a physical plate such as offset printing, gravure printing, letterpress printing, intaglio printing, or screen printing. You can print in time. A plate for printing a periodic pattern may be used to print a design on a substrate that is a product or a product package. When using a physical plate, there is an advantage of being able to print at high speed and at a low cost, and when using an electronic plate, there is an advantage of being able to omit the step of making a plate.

In the present embodiment, for example, using a printing apparatus similar to the printing process for product packages, a unique moire pattern can be printed in the same printing process. It is possible to establish a one-to-one correspondence (hereinafter also referred to as "linking") with product packages.

(Distinguishability of moire pattern)
Through the manufacturing process as described above, while printing using the same periodic pattern and area markers, it is possible to create different moire patterns on individual print media constituting the print media group. Therefore, when two or more products are present, the products can be identified, for example, based on the difference in moiré pattern printed on the product package. Further, by recognizing the moire pattern by a collation system, which will be described later, it is also possible to authenticate each print medium individually.

(Application to traceability system)
This embodiment can be applied to a print medium on which a moire pattern is displayed on a part of a product or a part of a package of the product, and information such as a traceability code used for confirming the source of the product is added. can. "

A traceability system using a moire pattern matching system will be described with reference to FIG. In the figure, solid-line arrows indicate the flow of goods, and dotted-line arrows indicate the transmission of information. When the product is completed, the manufacturer 610 reads the product itself or the moire pattern printed on the product package with a reading device, converts it into image data, associates it with the image data of the moire pattern, and obtains various information about the product. , ID (also referred to as product information or unique information) to the cloud server (data processing device) 600 through the communication channel.

The cloud server 600 that receives the image data verifies the moire pattern and authenticates the individual code (checks for the same moire pattern), and then associates the moire pattern image data with the product information. Processing 650 is performed and stored in a predetermined storage area within the database. As the predetermined storage area, the authenticated moire pattern image data and the product information may be stored in the same folder, or the authenticated moire pattern image data and the product information may be stored in separate storage areas after being associated with each other. can be

In the traceability system, when the product passes through a wholesaler 620 or a retailer 630, a moire pattern is read by a reader or a communication terminal with a built-in reader at the timing of each arrival, shipment, etc. will be Then, the read moire pattern is converted into image data and sent to the cloud server 600 together with information such as location, distribution channel information, and price (hereinafter referred to as "additional information"). Reading of these moiré patterns, conversion to image data, transmission of additional information, and the like are performed an arbitrary number of times in the distribution stage, and each time the amount of additional information accumulated in the cloud server increases.

The cloud server 600 that has received the image data and the additional information from the communication terminal performs processing 650 for associating the moire pattern with the additional information based on the image data, and adds information to the product information corresponding to the already stored moire pattern. , the additional information is additionally stored in a predetermined area of the database.

When a consumer 640 at the end of a distribution channel purchases a product, he/she reads the moiré pattern of the product package using a communication terminal with a moiré pattern reading function such as his/her own smartphone, and stores the product in the cloud server 600. You can inquire about product information, additional information, etc. In such a case, the cloud server 600, which has received the inquiry request together with the image data of the moiré pattern from the communication terminal, compares the received image data with the moiré patterns stored in the cloud server 600, and determines that the two match. In this case, the corresponding product information and additional information in the cloud server 600 are returned to the smart phone of the consumer 640 . The information transmitted at this time can also be said to be information indicating that the moire patterns match. Note that if there is no matching moire pattern, the cloud server 600 transmits information indicating that the moire patterns do not match to the communication terminal.

A consumer 640 who receives information indicating that the moire patterns match from the cloud server 600 can obtain information such as individual product information and additional information, and can use the information to make a purchase decision. Furthermore, the consumer 640 can also feed back the impression of consuming or using the product to the manufacturer 610 via the cloud server 600 by reading the moire pattern of the product package.

In this way, traceability systems using moire patterns are effective for all kinds of products, but they are particularly useful for agricultural products, marine products, jewelry, precious metals, handicrafts, works of art, etc., where the quality of individual products varies, as well as food and pharmaceuticals. It is particularly effective for items that require expiration date management and distribution/storage management.

For example, in the case of agricultural products, product information includes information such as the producer, region, use of pesticides and fertilizers, harvest time, water content, variety, taste such as sweetness, weight, and size. By using this system, wholesalers, retailers, and other distributors will be able to manage distribution and inventory for each product individually. In some cases, it is also possible to make detailed price decisions based on product information such as the time from the harvest time. Also, in the event of a defect or accident, it is possible to quickly collect the product and identify the cause. Consumers will be able to purchase products at acceptable prices and quality based on product information other than price and brand. By intervening in distribution, producers can learn real-time consumer trends that have been difficult to obtain, which can be useful for production planning, sales planning, product planning, etc. Conventionally, in order to attach an individual code to agricultural products, it was necessary to attach a sticker printed with a QR code or the like individually to each product. By using the print media according to this embodiment to generate moire patterns at low cost and using widely spread communication terminals such as smartphones, it is possible to construct a traceability system without incurring large costs. Become.

As described above, according to the present embodiment, different moire patterns can be expressed individually while printing with a printing device that prints the same pattern. , it becomes possible to generate a large amount of highly identifiable patterns at low cost. As a result, after mass-produced products are sold to consumers, a specific moire pattern can be selected by lottery, and prizes can be easily awarded only to consumers who have product packages with the same moire pattern. Therefore, it can be used for sales promotion of products.

Furthermore, since the generated moiré pattern has a large variation between various patterns, it can be said that the moiré pattern is an identification mark that has high reading accuracy and does not require an expensive collating device. In addition, the moire pattern has the advantage that it is easy to accurately determine the difference in pattern even if the pattern is slightly dirty or scratched. In addition, since it is possible to print on the product itself or on the same printing equipment that prints on the product package, there is an advantage that it does not take time to attach individual codes to products as tags or stickers. ing. Furthermore, unlike artificial metrics, moire patterns are identification marks that can be printed directly on products or product packages, so they also have the function of preventing fraud such as replacement. In addition, even if the moire pattern is reproduced by a scanner, a digital camera, or the like, a pattern different from the moire pattern is captured, making it difficult to forge. Further, even if the reading position of the reading device changes, reading with less erroneous determination is possible.

1 Verification system 2 Print medium 3 Communication terminal 4 Print pattern verification device 410 Inquiry information storage unit 420 Moire pattern extraction unit 430 Basic information storage unit 440 Moire pattern verification unit 200 Periodic pattern area 201 Periodic pattern area The maximum width 202 of the region in which the periodic pattern is provided The midpoint 205 of the maximum width of the region provided with the periodic pattern The regions 220, 221, 222, and 232 that are in the vicinity of the periodic pattern The first periodic patterns 230, 231, 223, and 233 The second periodic pattern 290 , 291, 292 Reference points 9, 900, 901, 902, 910, 920, 921, 930, 931, 932, 933, 940, 941, 950 Area marker 90Y Size of the area marker in the first direction 90X Size of second direction of area marker 90, 91, 92 Areas used for moire pattern discrimination 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251 Moire pattern of print medium 260 central portion 6 of moire pattern by closed curve periodic pattern base sheet 7C cyan plate cylinder 8M magenta plate cylinder 9Y yellow plate cylinder 10B black and first periodic pattern plate cylinder 11B second periodic pattern plate cylinder 7P-11P Impression cylinders 300, 310 Design 600 Cloud server 610 Manufacturer 620 Wholesaler 630 Retailer 640 Consumer

Claims (12)

A group of print media comprising at least two print media,
The print medium has a moire pattern generated by overlapping at least two periodic patterns commonly used in the print medium group,
The print medium includes an area marker commonly used for the print medium group,
A group of print media, wherein the print media are identifiable by differences in the moire patterns. 2. The print medium group according to claim 1, wherein the print medium has the area marker added to one of the at least two periodic patterns. 2. A difference in the magnitude of positional deviation of two periodic patterns, one of which includes the area marker, between any two print media is 1/50 or more of the average period of any one of the periodic patterns. Or the print media group according to 2. 4. The group of print media according to any one of claims 1 to 3, wherein at least part of the periodic pattern and the area markers of the print media are different in color. 5. The print medium group according to any one of claims 1 to 4, wherein the area marker is provided in an area outside the moire pattern area of the print medium. 6. The print medium group according to any one of claims 1 to 5, wherein the area marker is provided in an area inside the moire pattern area of the print medium. 7. The group of print media according to claim 1, wherein the shape of the area marker is a pattern combining arcs, straight lines, vertices, and corners. At least one area marker is formed on the print medium,
8. The printing medium group according to claim 1, wherein the total area of said area markers formed on said printing medium is within 95% of the area of said periodic pattern. A method for manufacturing a print medium group according to any one of claims 1 to 8,
a first step of printing a first periodic pattern on the print medium;
a second step of printing a second periodic pattern on the print medium so as to overlap at least part of the first periodic pattern;
and a third step of printing the area marker on the print medium inside or near a region where the first periodic pattern and the second periodic pattern overlap. 10. The method of manufacturing a print medium group according to claim 9, wherein the third step is performed simultaneously with at least one of the first step and the second step. A matching method for matching a first print medium and a second print medium, each having a moire pattern and a common area marker, comprising:
a substep of generating first print image data from the first print medium;
a sub-step of extracting a first moiré pattern and area markers from the generated first print image data and storing them as first moiré information;
a substep of generating second print image data from the second print medium;
a second extraction step comprising: a sub-step of extracting a second moiré pattern and area markers from the generated second print image data and storing them as second moiré information;
a matching step of matching the first moiré information and the second moiré information,
In the matching step, a first relative relationship between the first moiré pattern and the area marker obtained based on the first moiré information, and the second moiré pattern obtained based on the second moiré information. comparing two moire patterns with a second relative relationship with the area marker;
A printing medium collation method for determining that the first printing medium and the second printing medium are the same when the first relative relationship and the second relative relationship match. 12. The print medium collation according to claim 11, wherein if the first relative relationship and the second relative relationship are different, it is determined that the first print medium and the second print medium are different. Method.

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